Voltage controlled oscillator circuit

Abstract

The invention provides a voltage controlled oscillator circuit, which consists of at least three stages of total difference unit circuits which are cascaded mutually and are completely same. The circuit has the advantages that: 1, the circuit is a CMOS voltage controlled oscillator circuit which has simple structure, high reliability, wide frequency regulating range, and can operate normally under extremely low power supply voltage; 2, the circuit can select a cascade mode of three-stage and above three-stage total difference units which are completely same; 3, source electrodes of positive feedback active load are directly earthed for improving one pass gain of the total difference units, thereby ensuring that the oscillator circuit can normally start oscillation under any condition; 4, a voltage clamping circuit plays a role of stabilizing amplitude of an output signal of the oscillator; and 5, when control voltage controls current in a tail current source of the difference unit to generate variation through certain V-I converting circuit, the oscillator circuit can generate output waveforms with different frequencies along with the magnitude of the tail current, as long as the current in the tail current source is invariable, the frequency of the output waveform of the oscillator circuit can be invariable.

Description

(1) Technical field: [0001] The invention relates to an oscillator circuit, in particular to a voltage-controlled oscillator circuit. (two) background technology: [0002] Most of the existing CMOS differential oscillator circuits can only be adjusted within a small frequency adjustment range. Occasionally, the circuit structure with wide adjustment range can neither work well under low voltage, but also makes the output waveform amplitude not stable enough, increases the phase noise of the oscillator circuit, and reduces the anti-noise ability of the entire circuit system. Such oscillating circuits are increasingly unable to meet the needs of low voltage, low noise and wide frequency adjustment range. (3) Contents of the invention: [0003] The object of the present invention is to provide a voltage-controlled oscillator circuit, which is a CMOS voltage-controlled oscillator circuit with simple structure, high reliability, wide frequency adjustment range, and normal oper...

AI Technical Summary

Problems solved by technology

Occasionally, the circuit structure with wide adjustment range can not work well under low voltage, and the output waveform amplitude is not stable enough, which increases the phase noise of the oscillation circuit and reduces the anti-noise ability of the entire circuit system.

Such an oscillation circuit is increasingly unable to meet the needs of low voltage, low noise and wide frequency adjustment range

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